1. Field of the Invention
The present invention relates to a radiation detector component for converting an incident radiation into a light and detecting the converted light to photograph a radiation image and a radiation detector, and more particularly, to a radiation detector component a radiation detector for forming a two-dimensional array to photograph the radiation image.
2. Description of the Related Art
Conventionally, an X-ray CT apparatus used in medical institutes and the like photographs an internal structure of a patient by irradiating an X-ray on the patient. Specifically, the X-ray CT apparatus has an X-ray irradiation source and a radiation detector with a structure in which an X-ray detecting unit, which is arranged to be opposed to the X-ray irradiation source via the patient, is arranged in a one-dimensional array shape. The detector has a function of converting a received X-ray into an electric signal and includes a scintillator element that converts the X-ray into a visible ray and a photodiode element that converts the visible ray into an electric signal. The X-ray CT apparatus receives an X-ray that has passed through the patient with this radiation detector and records an electric signal obtained based on this X-ray received. The X-ray CT apparatus varies an angle for irradiating an X-ray to repeat reception of the X-ray while maintaining a positional relation between the X-ray irradiation source and the radiation detector. Thereafter, the X-ray CT apparatus applies processing such as convolution and back-projection to the electric signal obtained to reconstitute an image of a section (a slice) of the patient through which the X-ray has passed.
In particular, in recent years, in a multi-slice X-ray CT apparatus that can simultaneously photograph a plurality of slices by irradiating an X-ray once, a plurality of array-like X-ray detecting units are arranged in association with the slices. The multi-slice X-ray CT apparatus collects X-rays, which have passed through the respective slices, to reconstitute slice images. Therefore, the multi-slice X-ray CT apparatus includes a radiation detector in which the detecting units are arranged in a two-dimensional array shape rather than a one-dimensional array shape.
As a conventional radiation detector, there is a radiation detector in which scintillator elements and photodiode elements are arranged to be adjacent to each other with respect to an incidence direction of a radiation and detection surfaces of the photodiode elements are arranged substantially parallel to the incidence direction of the radiation (see, for example, Japanese Patent Application Laid-Open No. 2003-84066).
In the conventional radiation detector, thickness of a reflection film applied on surfaces that are peripheral edges of the scintillator elements and substantially parallel to the incidence direction of the radiation is added to thickness of a substrate forming the photodiode elements. Thus, there is a problem in that a detection area for the radiation viewed from the incidence direction of the radiation decreases, detection sensitivity falls, and it is impossible to obtain high resolution.